Results for "Stefan Luettgen"
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Analyzing Business Process Anomalies Using AutoencodersMar 03 2018Businesses are naturally interested in detecting anomalies in their internal processes, because these can be indicators for fraud and inefficiencies. Within the domain of business intelligence, classic anomaly detection is not very frequently researched. ... More BINet: Multi-perspective Business Process Anomaly ClassificationFeb 08 2019In this paper, we introduce BINet, a neural network architecture for real-time multi-perspective anomaly detection in business process event logs. BINet is designed to handle both the control flow and the data perspective of a business process. Additionally, ... More The midpoint between dipole and parton showersJun 16 2015Sep 19 2015We present a new parton-shower algorithm. Borrowing from the basic ideas of dipole cascades, the evolution variable is judiciously chosen as the transverse momentum in the soft limit. This leads to a very simple analytic structure of the evolution. A ... More Stochastic mortality models: An infinite dimensional approachJul 11 2019Demographic projections of future mortality rates involve a high level of uncertainty and require stochastic mortality models. The current paper investigates forward mortality models driven by a (possibly infinite dimensional) Wiener process and a compensated ... More Weak Limit of the 3-State Quantum Walk on the LineApr 04 2014May 21 2014We revisit the one dimensional discrete time quantum walk with 3 states and the Grover coin. We derive analytic expressions for observed the localization, an long time approximation for the probability density function (PDF). We also connect the time ... More Streaming KernelizationMay 06 2014Kernelization is a formalization of preprocessing for combinatorially hard problems. We modify the standard definition for kernelization, which allows any polynomial-time algorithm for the preprocessing, by requiring instead that the preprocessing runs ... More The H-Covariant Strong Picard GroupoidSep 08 2004Apr 25 2005The notion of H-covariant strong Morita equivalence is introduced for *-algebras over C = R(i) with an ordered ring R which are equipped with a *-action of a Hopf *-algebra H. This defines a corresponding H-covariant strong Picard groupoid which encodes ... More Reliability of regulatory networks and its evolutionMay 27 2008The problem of reliability of the dynamics in biological regulatory networks is studied in the framework of a generalized Boolean network model with continuous timing and noise. Using well-known artificial genetic networks such as the repressilator, we ... More Reliability of genetic networks is evolvableJul 10 2007Control of the living cell functions with remarkable reliability despite the stochastic nature of the underlying molecular networks -- a property presumably optimized by biological evolution. We here ask to what extent the property of a stochastic dynamical ... More Tests of Quantum Chromo Dynamics at e^+e^- CollidersMar 06 2006May 23 2006The current status of tests of the theory of strong interactions, Quantum Chromo Dynamics (QCD), with data from hadron production in e^+e^- annihilation experiments is reviewed. The LEP experiments ALEPH, DELPHI, L3 and OPAL have published many analyses ... More Non critical super strings on world sheets of constant curvatureOct 30 1992Nov 03 1992We consider correlation functions in Neveu--Schwarz string theory coupled to two dimensional gravity. The action for the 2D gravity consists of the string induced Liouville action and the Jackiw--Teitelboim action describing pure 2D gravity. Then gravitational ... More Lattice QCD with a chiral twistFeb 05 2007In these lectures I explain how chiral symmetry of continuum QCD naturally leads to a class of lattice regularisations known as twisted mass QCD (tmQCD). As compared to standard Wilson quarks, its advantages are the absence of unphysical zero modes, the ... More One-loop renormalization of the QCD Schrödinger functionalApr 08 1995In a previous publication, we have constructed the Schr\"odinger functional in Wilson's lattice QCD. It was found that the naive continuum limit leads to a well-defined classical continuum theory. Starting from the latter, a formal continuum definition ... More Separable linear orders and universalityJun 01 2016In various places in the literature it is stated that every separable linear order embeds into the real line. This is, however, not the case, at least not with respect to the usual definition of separability. We correct this misconception. Convergence of the gradient method for ill-posed problemsJun 01 2016We study the convergence of the gradient descent method for solving ill-posed problems where the solution is characterized as a global minimum of a differentiable functional in a Hilbert space. The classical least-squares functional for nonlinear operator ... More Novikov homology and noncommutative Alexander polynomialsJun 11 2016In the early 2000's Cochran and Harvey introduced non-commutative Alexander polynomials for 3-manifolds. Their degrees give strong lower bounds on the Thurston norm. In this paper we make the case that the vanishing of a certain Novikov-Sikorav homology ... More An example of quantum imaging: rendering an object undetectableApr 26 2016In this paper we propose and analyse a Gedankenexperiment involving three non-linear crystals and two objects inserted in the idler beams. We show that, besides the behaviour that can be extrapolated from previous experiments involving two crystals and ... More Starburst galaxies as seen by gamma-ray telescopesJan 24 2016Starburst galaxies have a highly increased star-formation rate compared to regular galaxies and inject huge amounts of kinetic power into the interstellar medium via supersonic stellar winds, and supernova explosions. Supernova remnants, which are considered ... More Lower Bounds on the mim-width of Some Perfect Graph ClassesAug 04 2016mim-width is a recent graph width measure that has seen applications in graph algorithms and problems related to propositional satisfiability. In this paper, we show linear lower bounds for the mim-width of strongly chordal split graphs, co-comparability ... More Cyclotomic Aperiodic Substitution TilingsJun 22 2016Sep 27 2016The class of Cyclotomic Aperiodic Substitution Tilings (CAST) is introduced. Its vertices are supported on the 2n-th cyclotomic field. It covers a wide range of known aperiodic substitution tilings of the plane with finite rotations. Substitution matrices ... More The Yang-Mills vacuum wave functional thirty-five years laterMar 04 2015The first paper attempting direct calculation of the Yang-Mills vacuum wave functional was published by Greensite in 1979. I review some recent results of the determination of the vacuum wave functional in Monte Carlo simulations of SU(2) lattice gauge ... More Geometry on totally separably closed schemesMar 10 2015We prove, for quasicompact separated schemes over ground fields, that Cech cohomology coincides with sheaf cohomology with respect to the Nisnevich topology. This is a partial generalization of Artin's result that for noetherian schemes such an equality ... More Covariant Strong Morita Theory of Star Product AlgebrasJan 27 2009In this note we recall some recent progress in understanding the representation theory of *-algebras over rings C = R(i) where R is ordered and i^2 = -1. The representation spaces are modules over auxiliary *-algebras with inner products taking values ... More Omega_bbb excited-state spectroscopy from lattice QCDFeb 11 2013Triply heavy baryons are very interesting systems analogous to heavy quarkonia, but are difficult to access experimentally. Lattice QCD can provide precise predictions for these systems, which can be compared to other theoretical approaches. In this work, ... More Prediction of the Omega_bbb mass from lattice QCDAug 18 2010Oct 27 2010The mass of the triply heavy baryon Omega_bbb is calculated in lattice QCD with 2+1 flavors of light sea quarks. The b quark is implemented with improved lattice NRQCD. Gauge field ensembles from both the RBC/UKQCD and MILC collaborations with lattice ... More JyNI - Using native CPython-Extensions in JythonApr 25 2014Apr 29 2014Jython is a Java based Python implementation and the most seamless way to integrate Python and Java. However, it does not support native extensions written for CPython like NumPy or SciPy. Since most scientific Python code fundamentally depends on exactly ... More Probabilistic Constraint Logic ProgrammingNov 11 1997This paper addresses two central problems for probabilistic processing models: parameter estimation from incomplete data and efficient retrieval of most probable analyses. These questions have been answered satisfactorily only for probabilistic regular ... More An uncertainty principle on compact manifoldsNov 05 2014Breitenberger's uncertainty principle on the torus $\mathbb{T}$ and its higher-dimensional analogue on $\mathbb{S}^{d-1}$ are well understood. We give describe an entire family of uncertainty principles on compact manifolds $(M,g)$, which includes the ... More Directional Poincare inequalities along mixing flowsApr 22 2015Mar 11 2016We provide a refinement of the Poincar\'{e} inequality on the torus $\mathbb{T}^d$: there exists a Lebesgue-null set $\mathcal{B} \subset \mathbb{T}^d$ of directions such that for every $\alpha \in \mathcal{B}$ there is a $c_{\alpha} > 0$ with $$ \|\nabla ... More On Eigenvectors of Random Band Matrices with Large BandJul 22 2013Oct 21 2014We study random, symmetric $N \times N$ band matrices with a band of size $W$ and Bernoulli random variables as entries. This interpolates between nearest neighbour interaction $W = 1$ and Wigner matrices $W = N$. Eigenvectors are known to be localized ... More Aging Random WalksFeb 15 1997Aging refers to the property of two-time correlation functions to decay very slowly on (at least) two time scales. This phenomenon has gained recent attention due to experimental observations of the history dependent relaxation behavior in amorphous materials ... More Spin Glass Stiffness in zero DimensionsApr 11 2006A unique analytical result for the Migdal-Kadanoff hierarchical lattice is obtained. The scaling of the defect energy for a zero-dimensional spin glass is derived for a bond distribution that is continuous at the origin. The value of the ``stiffness'' ... More Feynman integrals and multiple polylogarithmsMay 07 2007May 10 2007In this talk I review the connections between Feynman integrals and multiple polylogarithms. After an introductory section on loop integrals I discuss the Mellin-Barnes transformation and shuffle algebras. In a subsequent section multiple polylogarithms ... More The Art of Computing Loop IntegralsApr 07 2006A perturbative approach to quantum field theory involves the computation of loop integrals, as soon as one goes beyond the leading term in the perturbative expansion. First I review standard techniques for the computation of loop integrals. In a second ... More Cancellation of infrared divergences at NNLOOct 14 2003Perturbative calculations at next-to-next-to-leading order for multi-particle final states require a method to cancel infrared singularities. I discuss how to setup the subtraction method at NNLO. Status of jet cross sections to NNLOJun 29 2006I review the state-of-the-art for fully differential numerical NNLO programs. Topics which are covered include the calculation of two-loop amplitudes, multiple polylogarithms, cancellation of infra-red divergences at NNLO and the efficient generation ... More QCD corrections to e+ e- --> 4 jetsNov 30 1999We report on the next-to-leading order QCD calculation for e+ e- --> 4 jets. We explain some modern techniques which have been used to calculate the one-loop amplitudes efficiently. We further report on the general purpose numerical program ``Mercutio'', ... More Coupling the Superstring to a D-Brane Ramond-Ramond BackgroundAug 13 2001Dec 03 2001We propose a new approach for coupling the type II superstring to the Ramond-Ramond background of D-branes in the RNS formalism, alternative to introducing RR vertex operators. It is based on the mixing between Ramond-Ramond p-form excitations in the ... More Lower bounds on the absorption probability of beam splittersAug 25 2005We derive a lower limit to the amount of absorptive loss present in passive linear optical devices such as a beam splitter. We choose a particularly simple beam splitter geometry, a single planar slab surrounded by vacuum, which already reveals the important ... More Note on the Lower Bounds of BimachinesApr 14 2018This is a brief note on the lower bound of bimachines. Particularly, we report that there is a class of functional transducers with $O(n)$ states that do not admit a bimachine with fewer than $\Theta(2^n)$ states. LSTM Benchmarks for Deep Learning FrameworksJun 05 2018This study provides benchmarks for different implementations of LSTM units between the deep learning frameworks PyTorch, TensorFlow, Lasagne and Keras. The comparison includes cuDNN LSTMs, fused LSTM variants and less optimized, but more flexible LSTM ... More Geometric Microlocal Analysis in Denjoy-Carleman classesMay 29 2018A systematic geometric theory for the ultradifferentiable (non-quasianalytic and quasianalytic) wavefront set similar to the well-known theory in the classic smooth and analytic setting is developed. In particular an analogue of Bony's Theorem and the ... More Manifestly Lorentz-Invariant Baryon Chiral Perturbation TheorySep 19 2005A successful effective field theory program requires besides the most general effective Lagrangian a perturbative expansion scheme for observables in terms of a consistent power counting method. We discuss a renormalization scheme for manifestly Lorentz-invariant ... More Recent developments in effective field theoryNov 02 2007We will give a short introduction to the one-nucleon sector of chiral perturbation theory and will address the issue of a consistent power counting and renormalization. We will discuss the infrared regularization and the extended on-mass-shell scheme. ... More Relative entropy for coherent states in chiral CFTMar 18 2019We consider the relative entropy between the vacuum state and a state obtained by applying an exponentiated stress tensor to the vacuum of a chiral conformal field theory on the lightray. The smearing function of the stress tensor can be viewed as a vector ... More Yet Another Paper about Partial Verb Phrase Fronting in GermanMay 02 1996I describe a very simple HPSG analysis for partial verb phrase fronting. I will argue that the presented account is more adequate than others made during the past years because it allows the description of constituents in fronted positions with their ... More A Nonlocal Functional Promoting Low-Discrepancy Point SetsFeb 01 2019Let $X = \left\{x_1, \dots, x_N\right\} \subset \mathbb{T}^d \cong [0,1]^d$ be a set of $N$ points in the $d-$dimensional torus that we want to arrange as regularly possible. The purpose of this paper is to introduce a curious energy functional $$ E(X) ... More Refined Seiberg-Witten invariantsDec 31 2003This is a survey article on the stable cohomotopy refinement of Seiberg-Witten invariants containing also new results, for example: - Stable cohomotopy groups describe path components of certain mapping spaces. - Relation of stable cohomotopy invariants ... More Quantum Integration in Sobolev ClassesDec 23 2001We study high dimensional integration in the quantum model of computation. We develop quantum algorithms for integration of functions from Sobolev classes $W^r_p([0,1]^d)$ and analyze their convergence rates. We also prove lower bounds which show that ... More